European Pine Sawfly

Pest Description

• adults: 1/3 inch; males are mostly black with feathery antennae; females are reddish brown
• larvae: caterpillarlike and ~ 1 inch; green body with white, green and gray/black stripes; shiny black head
• larvae will rear their heads when disturbed

Host Plants, Diet & Damage

• mugo pine; other pine species
• prefer to consume older needles from tip to base
• larvae often feed in groups
• brown scars on needles where eggs have been inserted

Biology, Life Cycle & Damaging Life Stage

• overwinter as eggs inside needles
• eggs hatch in mid-spring and larvae feed on old needles
• pupate on host bark or around the host in early to mid-summer
• adults emerge in late summer to mate and lay eggs in needles
• one generation per year
• larvae are the primary damaging stage

IPM Recommendations

• Manage trees to improve or maintain health.
• Monitor in fall through early spring for egg-laying scars on needles and in the spring for damage to old needles and larvae (late-April to early-May).
• Low-level infestations can be tolerated.
• Wash larvae off with a strong spray of water.
• Spot-treat young larvae with an insecticide (azadirachtin; horticultural oil; insecticidal soap; organophosphate; pyrethroid; spinosyn) when monitoring indicates their presence.